git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/util/ser.rs

   1 //! A very simple serialization framework which is used to serialize/deserialize messages as well
   2 //! as ChannelsManagers and ChannelMonitors.
   3
   4 use std::result::Result;
   5 use std::io::{Read, Write};
   6 use std::collections::HashMap;
   7 use std::hash::Hash;
   8 use std::sync::Mutex;
   9 use std::cmp;
  10
  11 use bitcoin::secp256k1::Signature;
  12 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
  13 use bitcoin::blockdata::script::Script;
  14 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
  15 use bitcoin::consensus;
  16 use bitcoin::consensus::Encodable;
  17 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
  18 use bitcoin::hash_types::{Txid, BlockHash};
  19 use std::marker::Sized;
  20 use ln::msgs::DecodeError;
  21 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
  22 use util::byte_utils;
  23
  24 use util::byte_utils::{be64_to_array, be48_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be48, slice_to_be64};
  25
  26 const MAX_BUF_SIZE: usize = 64 * 1024;
  27
  28 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
  29 /// buffers being written into.
  30 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
  31 /// hints.
  32 pub trait Writer {
  33         /// Writes the given buf out. See std::io::Write::write_all for more
  34         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
  35         /// Hints that data of the given size is about the be written. This may not always be called
  36         /// prior to data being written and may be safely ignored.
  37         fn size_hint(&mut self, size: usize);
  38 }
  39
  40 impl<W: Write> Writer for W {
  41         #[inline]
  42         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  43                 <Self as ::std::io::Write>::write_all(self, buf)
  44         }
  45         #[inline]
  46         fn size_hint(&mut self, _size: usize) { }
  47 }
  48
  49 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  50 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  51         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  52                 self.0.write_all(buf)
  53         }
  54         fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
  55                 self.0.write_all(buf)?;
  56                 Ok(buf.len())
  57         }
  58         fn flush(&mut self) -> Result<(), ::std::io::Error> {
  59                 Ok(())
  60         }
  61 }
  62
  63 pub(crate) struct VecWriter(pub Vec<u8>);
  64 impl Writer for VecWriter {
  65         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  66                 self.0.extend_from_slice(buf);
  67                 Ok(())
  68         }
  69         fn size_hint(&mut self, size: usize) {
  70                 self.0.reserve_exact(size);
  71         }
  72 }
  73
  74 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  75 /// of some data when serialized but don't yet need the full data.
  76 pub(crate) struct LengthCalculatingWriter(pub usize);
  77 impl Writer for LengthCalculatingWriter {
  78         #[inline]
  79         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  80                 self.0 += buf.len();
  81                 Ok(())
  82         }
  83         #[inline]
  84         fn size_hint(&mut self, _size: usize) {}
  85 }
  86
  87 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
  88 /// forward to ensure we always consume exactly the fixed length specified.
  89 pub(crate) struct FixedLengthReader<R: Read> {
  90         read: R,
  91         bytes_read: u64,
  92         total_bytes: u64,
  93 }
  94 impl<R: Read> FixedLengthReader<R> {
  95         pub fn new(read: R, total_bytes: u64) -> Self {
  96                 Self { read, bytes_read: 0, total_bytes }
  97         }
  98
  99         pub fn bytes_remain(&mut self) -> bool {
 100                 self.bytes_read != self.total_bytes
 101         }
 102
 103         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 104                 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
 105                 if self.bytes_read != self.total_bytes {
 106                         Err(DecodeError::ShortRead)
 107                 } else {
 108                         Ok(())
 109                 }
 110         }
 111 }
 112 impl<R: Read> Read for FixedLengthReader<R> {
 113         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 114                 if self.total_bytes == self.bytes_read {
 115                         Ok(0)
 116                 } else {
 117                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 118                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 119                                 Ok(v) => {
 120                                         self.bytes_read += v as u64;
 121                                         Ok(v)
 122                                 },
 123                                 Err(e) => Err(e),
 124                         }
 125                 }
 126         }
 127 }
 128
 129 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
 130 /// between "EOF reached before we started" and "EOF reached mid-read".
 131 pub(crate) struct ReadTrackingReader<R: Read> {
 132         read: R,
 133         pub have_read: bool,
 134 }
 135 impl<R: Read> ReadTrackingReader<R> {
 136         pub fn new(read: R) -> Self {
 137                 Self { read, have_read: false }
 138         }
 139 }
 140 impl<R: Read> Read for ReadTrackingReader<R> {
 141         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 142                 match self.read.read(dest) {
 143                         Ok(0) => Ok(0),
 144                         Ok(len) => {
 145                                 self.have_read = true;
 146                                 Ok(len)
 147                         },
 148                         Err(e) => Err(e),
 149                 }
 150         }
 151 }
 152
 153 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
 154 pub trait Writeable {
 155         /// Writes self out to the given Writer
 156         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
 157
 158         /// Writes self out to a Vec<u8>
 159         fn encode(&self) -> Vec<u8> {
 160                 let mut msg = VecWriter(Vec::new());
 161                 self.write(&mut msg).unwrap();
 162                 msg.0
 163         }
 164
 165         /// Writes self out to a Vec<u8>
 166         fn encode_with_len(&self) -> Vec<u8> {
 167                 let mut msg = VecWriter(Vec::new());
 168                 0u16.write(&mut msg).unwrap();
 169                 self.write(&mut msg).unwrap();
 170                 let len = msg.0.len();
 171                 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
 172                 msg.0
 173         }
 174 }
 175
 176 impl<'a, T: Writeable> Writeable for &'a T {
 177         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> { (*self).write(writer) }
 178 }
 179
 180 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 181 pub trait Readable
 182         where Self: Sized
 183 {
 184         /// Reads a Self in from the given Read
 185         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 186 }
 187
 188 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
 189 /// from a Read given some additional set of arguments which is required to deserialize.
 190 pub trait ReadableArgs<P>
 191         where Self: Sized
 192 {
 193         /// Reads a Self in from the given Read
 194         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 195 }
 196
 197 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
 198 pub trait MaybeReadable
 199         where Self: Sized
 200 {
 201         /// Reads a Self in from the given Read
 202         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 203 }
 204
 205 pub(crate) struct U48(pub u64);
 206 impl Writeable for U48 {
 207         #[inline]
 208         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 209                 writer.write_all(&be48_to_array(self.0))
 210         }
 211 }
 212 impl Readable for U48 {
 213         #[inline]
 214         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 215                 let mut buf = [0; 6];
 216                 reader.read_exact(&mut buf)?;
 217                 Ok(U48(slice_to_be48(&buf)))
 218         }
 219 }
 220
 221 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
 222 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 223 ///
 224 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 225 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 226 /// you're looking for an example of a variable-length integer to use for your own project, move
 227 /// along, this is a rather poor design.
 228 pub(crate) struct BigSize(pub u64);
 229 impl Writeable for BigSize {
 230         #[inline]
 231         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 232                 match self.0 {
 233                         0...0xFC => {
 234                                 (self.0 as u8).write(writer)
 235                         },
 236                         0xFD...0xFFFF => {
 237                                 0xFDu8.write(writer)?;
 238                                 (self.0 as u16).write(writer)
 239                         },
 240                         0x10000...0xFFFFFFFF => {
 241                                 0xFEu8.write(writer)?;
 242                                 (self.0 as u32).write(writer)
 243                         },
 244                         _ => {
 245                                 0xFFu8.write(writer)?;
 246                                 (self.0 as u64).write(writer)
 247                         },
 248                 }
 249         }
 250 }
 251 impl Readable for BigSize {
 252         #[inline]
 253         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 254                 let n: u8 = Readable::read(reader)?;
 255                 match n {
 256                         0xFF => {
 257                                 let x: u64 = Readable::read(reader)?;
 258                                 if x < 0x100000000 {
 259                                         Err(DecodeError::InvalidValue)
 260                                 } else {
 261                                         Ok(BigSize(x))
 262                                 }
 263                         }
 264                         0xFE => {
 265                                 let x: u32 = Readable::read(reader)?;
 266                                 if x < 0x10000 {
 267                                         Err(DecodeError::InvalidValue)
 268                                 } else {
 269                                         Ok(BigSize(x as u64))
 270                                 }
 271                         }
 272                         0xFD => {
 273                                 let x: u16 = Readable::read(reader)?;
 274                                 if x < 0xFD {
 275                                         Err(DecodeError::InvalidValue)
 276                                 } else {
 277                                         Ok(BigSize(x as u64))
 278                                 }
 279                         }
 280                         n => Ok(BigSize(n as u64))
 281                 }
 282         }
 283 }
 284
 285 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 286 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 287 /// encapsulates such integers implementing Readable/Writeable for them.
 288 #[cfg_attr(test, derive(PartialEq, Debug))]
 289 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
 290
 291 macro_rules! impl_writeable_primitive {
 292         ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
 293                 impl Writeable for $val_type {
 294                         #[inline]
 295                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 296                                 writer.write_all(&$meth_write(*self))
 297                         }
 298                 }
 299                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
 300                         #[inline]
 301                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 302                                 // Skip any full leading 0 bytes when writing (in BE):
 303                                 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
 304                         }
 305                 }
 306                 impl Readable for $val_type {
 307                         #[inline]
 308                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 309                                 let mut buf = [0; $len];
 310                                 reader.read_exact(&mut buf)?;
 311                                 Ok($meth_read(&buf))
 312                         }
 313                 }
 314                 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
 315                         #[inline]
 316                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
 317                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 318                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 319                                 // and then convert the appropriate number of bytes with extra high bytes out of
 320                                 // buf.
 321                                 let mut buf = [0; $len*2];
 322                                 let mut read_len = reader.read(&mut buf[$len..])?;
 323                                 let mut total_read_len = read_len;
 324                                 while read_len != 0 && total_read_len != $len {
 325                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 326                                         total_read_len += read_len;
 327                                 }
 328                                 if total_read_len == 0 || buf[$len] != 0 {
 329                                         let first_byte = $len - ($len - total_read_len);
 330                                         Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
 331                                 } else {
 332                                         // If the encoding had extra zero bytes, return a failure even though we know
 333                                         // what they meant (as the TLV test vectors require this)
 334                                         Err(DecodeError::InvalidValue)
 335                                 }
 336                         }
 337                 }
 338         }
 339 }
 340
 341 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
 342 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
 343 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
 344
 345 impl Writeable for u8 {
 346         #[inline]
 347         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 348                 writer.write_all(&[*self])
 349         }
 350 }
 351 impl Readable for u8 {
 352         #[inline]
 353         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 354                 let mut buf = [0; 1];
 355                 reader.read_exact(&mut buf)?;
 356                 Ok(buf[0])
 357         }
 358 }
 359
 360 impl Writeable for bool {
 361         #[inline]
 362         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 363                 writer.write_all(&[if *self {1} else {0}])
 364         }
 365 }
 366 impl Readable for bool {
 367         #[inline]
 368         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 369                 let mut buf = [0; 1];
 370                 reader.read_exact(&mut buf)?;
 371                 if buf[0] != 0 && buf[0] != 1 {
 372                         return Err(DecodeError::InvalidValue);
 373                 }
 374                 Ok(buf[0] == 1)
 375         }
 376 }
 377
 378 // u8 arrays
 379 macro_rules! impl_array {
 380         ( $size:expr ) => (
 381                 impl Writeable for [u8; $size]
 382                 {
 383                         #[inline]
 384                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 385                                 w.write_all(self)
 386                         }
 387                 }
 388
 389                 impl Readable for [u8; $size]
 390                 {
 391                         #[inline]
 392                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 393                                 let mut buf = [0u8; $size];
 394                                 r.read_exact(&mut buf)?;
 395                                 Ok(buf)
 396                         }
 397                 }
 398         );
 399 }
 400
 401 //TODO: performance issue with [u8; size] with impl_array!()
 402 impl_array!(3); // for rgb
 403 impl_array!(4); // for IPv4
 404 impl_array!(10); // for OnionV2
 405 impl_array!(16); // for IPv6
 406 impl_array!(32); // for channel id & hmac
 407 impl_array!(33); // for PublicKey
 408 impl_array!(64); // for Signature
 409 impl_array!(1300); // for OnionPacket.hop_data
 410
 411 // HashMap
 412 impl<K, V> Writeable for HashMap<K, V>
 413         where K: Writeable + Eq + Hash,
 414               V: Writeable
 415 {
 416         #[inline]
 417         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 418         (self.len() as u16).write(w)?;
 419                 for (key, value) in self.iter() {
 420                         key.write(w)?;
 421                         value.write(w)?;
 422                 }
 423                 Ok(())
 424         }
 425 }
 426
 427 impl<K, V> Readable for HashMap<K, V>
 428         where K: Readable + Eq + Hash,
 429               V: Readable
 430 {
 431         #[inline]
 432         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 433                 let len: u16 = Readable::read(r)?;
 434                 let mut ret = HashMap::with_capacity(len as usize);
 435                 for _ in 0..len {
 436                         ret.insert(K::read(r)?, V::read(r)?);
 437                 }
 438                 Ok(ret)
 439         }
 440 }
 441
 442 // Vectors
 443 impl Writeable for Vec<u8> {
 444         #[inline]
 445         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 446                 (self.len() as u16).write(w)?;
 447                 w.write_all(&self)
 448         }
 449 }
 450
 451 impl Readable for Vec<u8> {
 452         #[inline]
 453         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 454                 let len: u16 = Readable::read(r)?;
 455                 let mut ret = Vec::with_capacity(len as usize);
 456                 ret.resize(len as usize, 0);
 457                 r.read_exact(&mut ret)?;
 458                 Ok(ret)
 459         }
 460 }
 461 impl Writeable for Vec<Signature> {
 462         #[inline]
 463         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 464                 (self.len() as u16).write(w)?;
 465                 for e in self.iter() {
 466                         e.write(w)?;
 467                 }
 468                 Ok(())
 469         }
 470 }
 471
 472 impl Readable for Vec<Signature> {
 473         #[inline]
 474         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 475                 let len: u16 = Readable::read(r)?;
 476                 let byte_size = (len as usize)
 477                                 .checked_mul(33)
 478                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 479                 if byte_size > MAX_BUF_SIZE {
 480                         return Err(DecodeError::BadLengthDescriptor);
 481                 }
 482                 let mut ret = Vec::with_capacity(len as usize);
 483                 for _ in 0..len { ret.push(Signature::read(r)?); }
 484                 Ok(ret)
 485         }
 486 }
 487
 488 impl Writeable for Script {
 489         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 490                 (self.len() as u16).write(w)?;
 491                 w.write_all(self.as_bytes())
 492         }
 493 }
 494
 495 impl Readable for Script {
 496         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 497                 let len = <u16 as Readable>::read(r)? as usize;
 498                 let mut buf = vec![0; len];
 499                 r.read_exact(&mut buf)?;
 500                 Ok(Script::from(buf))
 501         }
 502 }
 503
 504 impl Writeable for PublicKey {
 505         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 506                 self.serialize().write(w)
 507         }
 508 }
 509
 510 impl Readable for PublicKey {
 511         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 512                 let buf: [u8; 33] = Readable::read(r)?;
 513                 match PublicKey::from_slice(&buf) {
 514                         Ok(key) => Ok(key),
 515                         Err(_) => return Err(DecodeError::InvalidValue),
 516                 }
 517         }
 518 }
 519
 520 impl Writeable for SecretKey {
 521         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 522                 let mut ser = [0; 32];
 523                 ser.copy_from_slice(&self[..]);
 524                 ser.write(w)
 525         }
 526 }
 527
 528 impl Readable for SecretKey {
 529         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 530                 let buf: [u8; 32] = Readable::read(r)?;
 531                 match SecretKey::from_slice(&buf) {
 532                         Ok(key) => Ok(key),
 533                         Err(_) => return Err(DecodeError::InvalidValue),
 534                 }
 535         }
 536 }
 537
 538 impl Writeable for Sha256dHash {
 539         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 540                 w.write_all(&self[..])
 541         }
 542 }
 543
 544 impl Readable for Sha256dHash {
 545         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 546                 use bitcoin::hashes::Hash;
 547
 548                 let buf: [u8; 32] = Readable::read(r)?;
 549                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 550         }
 551 }
 552
 553 impl Writeable for Signature {
 554         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 555                 self.serialize_compact().write(w)
 556         }
 557 }
 558
 559 impl Readable for Signature {
 560         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 561                 let buf: [u8; 64] = Readable::read(r)?;
 562                 match Signature::from_compact(&buf) {
 563                         Ok(sig) => Ok(sig),
 564                         Err(_) => return Err(DecodeError::InvalidValue),
 565                 }
 566         }
 567 }
 568
 569 impl Writeable for PaymentPreimage {
 570         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 571                 self.0.write(w)
 572         }
 573 }
 574
 575 impl Readable for PaymentPreimage {
 576         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 577                 let buf: [u8; 32] = Readable::read(r)?;
 578                 Ok(PaymentPreimage(buf))
 579         }
 580 }
 581
 582 impl Writeable for PaymentHash {
 583         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 584                 self.0.write(w)
 585         }
 586 }
 587
 588 impl Readable for PaymentHash {
 589         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 590                 let buf: [u8; 32] = Readable::read(r)?;
 591                 Ok(PaymentHash(buf))
 592         }
 593 }
 594
 595 impl Writeable for PaymentSecret {
 596         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 597                 self.0.write(w)
 598         }
 599 }
 600
 601 impl Readable for PaymentSecret {
 602         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 603                 let buf: [u8; 32] = Readable::read(r)?;
 604                 Ok(PaymentSecret(buf))
 605         }
 606 }
 607
 608 impl<T: Writeable> Writeable for Option<T> {
 609         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 610                 match *self {
 611                         None => 0u8.write(w)?,
 612                         Some(ref data) => {
 613                                 let mut len_calc = LengthCalculatingWriter(0);
 614                                 data.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 615                                 BigSize(len_calc.0 as u64 + 1).write(w)?;
 616                                 data.write(w)?;
 617                         }
 618                 }
 619                 Ok(())
 620         }
 621 }
 622
 623 impl<T: Readable> Readable for Option<T>
 624 {
 625         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 626                 match BigSize::read(r)?.0 {
 627                         0 => Ok(None),
 628                         len => {
 629                                 let mut reader = FixedLengthReader::new(r, len - 1);
 630                                 Ok(Some(Readable::read(&mut reader)?))
 631                         }
 632                 }
 633         }
 634 }
 635
 636 impl Writeable for Txid {
 637         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 638                 w.write_all(&self[..])
 639         }
 640 }
 641
 642 impl Readable for Txid {
 643         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 644                 use bitcoin::hashes::Hash;
 645
 646                 let buf: [u8; 32] = Readable::read(r)?;
 647                 Ok(Txid::from_slice(&buf[..]).unwrap())
 648         }
 649 }
 650
 651 impl Writeable for BlockHash {
 652         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 653                 w.write_all(&self[..])
 654         }
 655 }
 656
 657 impl Readable for BlockHash {
 658         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 659                 use bitcoin::hashes::Hash;
 660
 661                 let buf: [u8; 32] = Readable::read(r)?;
 662                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
 663         }
 664 }
 665
 666 impl Writeable for OutPoint {
 667         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 668                 self.txid.write(w)?;
 669                 self.vout.write(w)?;
 670                 Ok(())
 671         }
 672 }
 673
 674 impl Readable for OutPoint {
 675         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 676                 let txid = Readable::read(r)?;
 677                 let vout = Readable::read(r)?;
 678                 Ok(OutPoint {
 679                         txid,
 680                         vout,
 681                 })
 682         }
 683 }
 684
 685 macro_rules! impl_consensus_ser {
 686         ($bitcoin_type: ty) => {
 687                 impl Writeable for $bitcoin_type {
 688                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 689                                 match self.consensus_encode(WriterWriteAdaptor(writer)) {
 690                                         Ok(_) => Ok(()),
 691                                         Err(consensus::encode::Error::Io(e)) => Err(e),
 692                                         Err(_) => panic!("We shouldn't get a consensus::encode::Error unless our Write generated an std::io::Error"),
 693                                 }
 694                         }
 695                 }
 696
 697                 impl Readable for $bitcoin_type {
 698                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 699                                 match consensus::encode::Decodable::consensus_decode(r) {
 700                                         Ok(t) => Ok(t),
 701                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == ::std::io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
 702                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e)),
 703                                         Err(_) => Err(DecodeError::InvalidValue),
 704                                 }
 705                         }
 706                 }
 707         }
 708 }
 709 impl_consensus_ser!(Transaction);
 710 impl_consensus_ser!(TxOut);
 711
 712 impl<T: Readable> Readable for Mutex<T> {
 713         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 714                 let t: T = Readable::read(r)?;
 715                 Ok(Mutex::new(t))
 716         }
 717 }
 718 impl<T: Writeable> Writeable for Mutex<T> {
 719         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 720                 self.lock().unwrap().write(w)
 721         }
 722 }
 723
 724 impl<A: Readable, B: Readable> Readable for (A, B) {
 725         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 726                 let a: A = Readable::read(r)?;
 727                 let b: B = Readable::read(r)?;
 728                 Ok((a, b))
 729         }
 730 }
 731 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 732         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 733                 self.0.write(w)?;
 734                 self.1.write(w)
 735         }
 736 }